The TARDIS returns to Peladon fifty years after its first visit, and the
Doctor and Sarah Jane find the planet in disorder once again. The
Federation desperately needs trisilicate -- in which Peladon is rich -- in
order to wage a war against the oppressive Galaxy Five. But this has lead
to claims amongst the natives of Peladon that the Federation is raping
their planet. To make matters worse, the ghost of Aggedor, the Sacred
Beast of Peladon, has been appearing, apparently condemning the
Federation. Once again it seems as if the Ice Warriors are to blame. Can
the Doctor be wrong twice?

Production

Brian Hayles' The Curse Of Peladon,
broadcast in early 1972, had proved popular with both the Doctor
Who production crew and audiences alike. Script editor Terrance Dicks
therefore decided at an early stage to feature a sequel as part of the
programme's eleventh season. Hayles was commissioned to write a storyline
under the title “Return To Peladon” on January 4th, 1973.
Dicks and producer Barry Letts asked Hayles to include both a feminist
element and some political relevance, as both felt that Doctor Who
was a valuable vehicle for social commentary.

Hayles originally approached “Return To Peladon” as a direct
sequel to the previous adventure, taking place only slightly later in the
reign of that serial's King Peladon. In this version of the story, Ortron
and Eckersley are working together to turn Peladon into an independent
world reaping the profit from the demand for trisilicate. Thalira is one
of the king's advisors -- who had been due to marry him but rejected him
following his affair with Jo Grant in The Curse Of
Peladon -- and Sarah and Eckersley are romantically involved.
Hayles' six scripts were commissioned on July 12th.

However, Letts and Dicks soon grew concerned that “Return To
Peladon” was becoming too complex, and Hayles worked with them to
streamline the plot. In the process, the setting was shifted forward fifty
years, with Thalira becoming the late King Peladon's heir; Serial YYY was
renamed The Monster Of Peladon. By late November, Dicks was still
unhappy with Hayles' work, and given that the writer had now produced two
radically different versions of the scripts, it was agreed that Hayles
would be paid for his work and Dicks would complete the serial himself.
The Monster Of Peladon consequently underwent numerous alterations
-- for instance, the Ice Warriors were originally defeated when the Doctor
manage to transmit word of their treachery to the Federation, who blockade
and threaten to destroy the Ice Warrior planet.

Letts made a conscious effort to reassemble as much of the crew of The Curse Of Peladon as possible for The
Monster Of Peladon. Most notably, Lennie Mayne returned as director,
having also helmed The Three Doctors in
between. Many of the sets, props and costumes from the earlier Peladon
story were also reused, resulting in tight continuity between the two
serials.

Work on The Monster Of Peladon began in 1974 with five days at the
Ealing Television Film Studios from January 14th to 18th, filming material
set in the mines. Studio recording then began with a two-day session in
BBC Television Centre Studio 8. Spanning Monday, January 28th and Tuesday
the 29th, this covered all the material for the first two episodes, as
well as the scenes set in the temple and the pit from part three. Shortly
thereafter, on February 8th, it was revealed to the press that Jon Pertwee
would be leaving Doctor Who at the end of Season Eleven.

Taping resumed with another Monday/Tuesday block on February 11th and
12th, this time in TC6, covering most of the remaining material for the
third and fourth installments. The Monster Of Peladon was completed
on Tuesday, February 26th and Wednesday the 27th, again in TC6. This
brought to a close Brian Hayles' involvement in televised Doctor
Who. He made further submissions to the production office which went
unproduced, and continued writing novelisations for Target's line of
Doctor Who books. Hayles also scripted a number of films and
television programmes, including the supernatural children's drama The
Moon Stallion, as well as the radio series The Archers. Brian
Hayles died on October 30th, 1978.

Meanwhile, Letts and Dicks had been hastily searching for a Fourth Doctor
in consultation with new Head of Serials Bill Slater. After considering
David Warner (at the time most renowned for his Shakespearean work, and
who felt that Doctor Who would be a backwards step for his career;
he later played an alternate Doctor in the Doctor Who Unbound audio
play Sympathy For The Devil from Big Finish Productions) and Ron
Moody (who had also been approached in 1969 to succeed Patrick Troughton),
the production team next thought about casting an older actor, in the vein
of the original Doctor, William Hartnell.

Several names were put forward and finally rejected: Carry On star
Jim Dale, who was interested but unavailable; Richard Hearne, who thought
Letts wanted him to play the Doctor in the vein of the Mister Pastry
character he had been portraying since 1949's Helter Skelter;
Michael Bentine of The Goon Show, who withdrew when he learned he
would not have script input; and Graham Crowden (later Soldeed in The Horns Of Nimon), who did not want to make a
longterm commitment to the series.

Letts and Dicks were seriously considering offering the role to Fulton
Mackay (who had played Dr Quinn in The
Silurians) when Slater received a letter on February 5th from an
actor named Tom Baker, with whom he had worked on an episode of Play Of
The Month. Baker had a variety of minor roles on his resume, including
episodes of Z Cars and the movies Nicholas And Alexandra and
Vault Of Horror, but had recently found himself out of work and
making ends meet as a construction labourer.

Thinking that Baker might be a suitable choice to play the new Doctor,
Slater encouraged Letts and Dicks to see the actor in the film The
Golden Voyage Of Sinbad. So impressed with Baker was Letts that he
discarded the “older Doctor” idea on the spot and quickly
offered Baker the starring role in Doctor Who. Baker was unveiled
to the press on February 15th; he was formally contracted for 26 episodes
four days later.

Sources

Doctor Who: The Handbook: The Third Doctor by David J Howe and
Stephen James Walker (1996), Virgin Publishing, ISBN 0 426 20486 7.